His works on ice cores were published in Jaworowski (1994, 1992) and in reports Jaworowski (1990, 1992).

Jaworowski has suggested that the long-term CO2 record is an artifact caused by the structural changes of the ice with depth and by postcoring processes. However, increases in CO2 and CH4 concentrations in the Vostok core are similar for the last two glacial-interglacial transitions, even though only the most recent transition is located in the brittle zone. Such evidence argues that the atmospheric trace-gas signal is not strongly affected by the presence of the brittle zone. [1]

Similarly Hans Oeschger [2] states that "...Some of (Jaworowski's) statements are drastically wrong from the physical point of view".

The data from shallow ice cores, such as those from Siple, Antarctica[5, 6], are widely used as a proof of man-made increase of CO2 content in the global atmosphere, notably by IPCC[7]. These data show a clear inverse correlation between the decreasing CO2 concentrations, and the load-pressure increasing with depth (Figure 1 A) . The problem with Siple data (and with other shallow cores) is that the CO2 concentration found in pre-industrial ice from a depth of 68 meters (i.e. above the depth of clathrate formation) was "too high". This ice was deposited in 1890 AD, and the CO2 concentration was 328 ppmv, not about 290 ppmv, as needed by man-made warming hypothesis. The CO2 atmospheric concentration of about 328 ppmv was measured at Mauna Loa, Hawaii as later as in 1973[8], i.e. 83 years after the ice was deposited at Siple.

An ad hoc assumption, not supported by any factual evidence[3, 9], solved the problem: the average age of air was arbitrary decreed to be exactly 83 years younger than the ice in which it was trapped. The "corrected" ice data were then smoothly aligned with the Mauna Loa record (Figure 1 B) , and reproduced in countless publications as a famous "Siple curve". Only thirteen years later, in 1993, glaciologists attempted to prove experimentally the "age assumption"[10], but they failed[9].

Jaworowski's article in ESPR is so hard to locate, it wouldn't be too unreasonable to suspect that the journal is not eager now for people to take much notice of it. But it did get noticed by one giant in climate science -- Hans Oeschger. Prof. Oeschger was the founder of the Division of Climate and Environmental Physics at the Physics Institute of the University of Bern. His name is attached to the Oeschger Counter that enabled Carbon-14 dating to be applied to geophysical problems, and to the Dansgaard-Oeschger 1,500 year cycle of slow cooling and abrupt warming observed in sediments and ice cores. He was active and influential in climate science until his death in 1998. His assessment of the Jaworowski article was blunt.